α-Al_2O_3载体的制备及其在环氧乙烷银催化剂中的应用  

α-Al_2O_3 Crystal Carriers:Preparation and Application in Ethylene Oxide Silver Catalysts

作　　者：苗壮[1,2] 史建公[2] 郝建薇[1] 范群波[1] 张敏宏[2] 

机构地区：[1]北京理工大学材料科学与工程学院,北京100081 [2]中国石化催化剂(北京)有限公司,北京102400

出　　处：《中外能源》2016年第2期60-68,共9页Sino-Global Energy

基　　金：中国石化催化剂有限公司科研项目(14-05-01)基金资助

摘　　要：银催化剂是工业上乙烯环氧化制备环氧乙烷的唯一催化剂,其性能直接影响装置的产能和产品的质量。银催化剂历经多年的发展,工业催化剂的选择性已经达到90%以上,性能得到了极大提高,载体研究也日趋成熟。对国内外主要商品银催化剂的性能进行了比较,工业上多以块状α-Al_2O_3或片状α-Al_2O_3为载体、块状α-Al_2O_3载体催化剂选择性较高,但活性略低,Ag含量低;片状α-Al_2O_3载体活性较高,但初期选择性略低,Ag含量高。开发活性好、选择性高和稳定性好的银催化剂仍然是业界追求的主题。通过载体后处理工艺改善载体表面结构和催化性能虽有一定效果,但工艺复杂,研究也仅局限于实验室阶段。利用原位改性α-Al_2O_3载体,仍然是银催化剂载体研究的主要方法。提高银催化剂的综合性能,需要从理论上进一步研究乙烯氧化制环氧乙烷反应的机理,从而为改进催化剂载体的结构和性能提供理论依据,并为选择银催化剂的助催化剂提供参考。Silver catalysts are the only available catalysts used in industrial preparation of ethylene oxide by oxidation of ethylene and their properties have a direct influence on the productivity of the production unit and product quality.Through years of development,the selectivity of industrial catalysts has exceeded 90%.The performance of these catalysts has improved significantly and their carriers are increasingly mature.This article compares the performance of major commercial silver catalysts in both the domestic and foreign markets.Most industrial applications use α-Al_2O_3 blocks or α-Al_2O_3 flakes as the carriers.α-Al_2O_3 block catalysts have higher selectivity but slightly lower activity and low Ag content.α-Al_2O_3 flake carriers have higher activity but slightly lower initial selectivity and high Ag content.The industry is still pursuing silver catalysts with good activity,high selectivity and good stability.Although it is somewhat effective to use carrier post-process- ing technology to improve the surface structure of the carrier and catalyst properties ,the process involved is complicated and studies are currently only limited to the laboratory stage.α-Al_2O_3 carrier in-situ modification remains the main method of studying silver catalyst carriers.To improve the overall performance of silver cata- lysts, researchers need to further study the principles of reactions involved in the preparation of ethylene ox- ide by oxidation of ethylene to provide theoretical basis for improving the structure and performance of cata- lyst carriers and provide reference for selecting promoters for silver catalysts.

关 键 词：α-Al_2O_3 环氧乙烷 银催化剂 载体 改性 

分 类 号：TQ426[化学工程] TQ223.26